This invention relates to a novel crystalline polymorphic form of sertraline hydrochloride, (1S-cis)-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-N-methyl-1-naphthalenam ine hydrochloride, and to a method for preparing it.
Sertraline hydrochloride has the chemical formula C.sub.17 H.sub.17 NCl.sub.2 .multidot.HCl and the following structural formula ##STR1## Its synthesis is described in U.S. Pat. No. 4,536,518, assigned to Pfizer Inc. Sertraline hydrochloride is useful as an antidepressant and anorectic agent, and is also useful in the treatment of chemical dependencies, anxiety-related disorders and premature ejaculation.
It has now been discovered that sertraline hydrochloride can exist as any of several novel crystalline forms, polymorphic forms, which differ from each other in their stability, physical properties, spectral data and methods of preparation. Five of these novel polymorphic forms are described in this application and are hereinafter referred to, respectively, as Form I, Form II, Form III, Form IV and Form V.
Of the five novel polymorphs referred to above, Form I, exhibits the greatest stability. Form I is characterized by a minimum of five years crystalline stability.
U.S. Pat. No. 4,536,518 does not refer to specific polymorphic crystalline forms of sertraline hydrochloride. The synthetic procedure described and exemplified in U.S. Pat. No. 4,536,518 produces the sertraline hydrochloride polymorph designated herein as Form II and described below. It does not suggest the existence of different polymorphic forms of sertraline.